1. Field of the Invention
The present invention relates to an optical touch panel, and more particularly to an optical touch panel having a light guide module.
2. Related Art
In recent years, a previous input manner of pressing a mechanical button begins to be replaced with an input manner in which a screen is contacted with an object or a finger. When a user contacts an image on the screen, a tactile feedback system on the screen may convert detected light ray data into an electronic signal and transfer the electronic signal to a processor, and the processor drives various electronic devices with a pre-programmed program, and thus vivid video and audio effects are presented through a screen picture.
A conventional tactile feedback system comprises a glass substrate, a Light Emitting Diode (LED), a photo-sensitive element, a lens, a reflecting element, and a light guide element. The photo-sensitive element, the LED and the lens are configured at an upper right corner of the glass substrate, and the reflecting sheet and the light guide element are simultaneously disposed at left and lower devices of the glass substrate.
The optical touch principle is to illuminate a distal reflecting component by a light emitting device, and when the finger or the contact object shields light rays, the photo-sensitive element may convert sensed and collected light ray changes into an electronic signal, and transfer the electronic signal to the processor to calculate a relative position of the finger or the contact object on the glass substrate. In order to enable the processor to precisely calculate the position of the finger on the glass substrate, internal components of an optical touch screen all need to be aligned repetitively and precisely. However, the number of the internal components of the optical touch screen in the prior art is excessively large, so the optical touch screen in the prior art is confronted with a complicated alignment problem.
Furthermore, the conventional optical touch screen reflects the light rays emitted by the light emitting device with the reflecting element to detect the relative position of the finger or the contact object on the glass substrate, so when the photo-sensitive element is receiving the light rays reflected by the reflecting element, a signal output by the photo-sensitive element is easily influenced by a surrounding light source. Likewise, the light rays reflected by the reflecting component and the light rays emitted by the light emitting device generate interference on the photo-sensitive element, thereby influencing the precision of sensing the light rays by the photo-sensitive element. Additionally, the light emitting device placed at the upper right corner of the glass substrate must illuminate the distal reflecting element, so a light emitting element of the optical touch screen in the prior art needs large brightness output and current input.